Selective signal receiving device



1951 H. A. STICKEL SELECTIVE SIGNAL REC EIVING DEVICE Filed July 22, 1950 4 Sheets-Sheet l INI/ENTOE, f/AROLQ A]. Sr/c1054 WWRk was 1951 H. A. STICKEL.

SELECTIVE} SIGNAL RECEIVING DEVICE 4 Sheets-Sheet 2 Filed July 22, 1950 INVEN TOR.

HAROLD A. sT/ CKEL Nov. 13, 1951 S-HCKEL 2,575,198

SELECTIVE SIGNAL RECEIVING DEVICE Filed July 22, 1950 4 Sheets-Sheet 3 Nov. 13, 1951 Y H. A. STICKEL 2,575,198

SELECTIVE SIGNAL RECEIVING DEVICE Filed July 22, 1950 4Sheets-Sheet 4 HIS ATTOENE Y Patented Nov. 13, 1951 UNITED STATES PATENT OFFICE SELECTIVE SIGNAL RECEIVING DEVICE Harold A. Stickel, San Francisco, Calif.

Application July 22, 1950, Serial No. 175,411

17 Claims.

This invention relates to selective signal receiving devices of the type suitable for operation by electrical signals in the form of integers. It is particularly applicable for conditioning a control element, such as an operating element of an electrical switch or a mechanism, at a remote station to energize a visual or aural signal device or to perform some function upon the reception of a predetermined code made up of one or more integer signals, e. g., in multi-party telephone networks, in radio networks wherein one or several of a group of radio receiving stations tuned to a common transmitting station is/are to be called, or for the remote control of various mechanisms.

The term integer signal is herein used to denote a signal made up of a sequence of rapidly recurring cycles of current changes the number of which is determined by the integer being transmitted; thus, the number of cycles may be equal to the value of the integer or to a multiple thereof or to a constant number added to the integer or to its multiple, etc., the integer zero being transmitted by a definite number of cycles different from that used for any other integer. The frequency of recurrence of the cycles of current change will depend upon the type of installation in question and may, for example, be of the order of ten per second in the case of dial-controlled circuits and of the order of one for every one or two seconds in the case of magnet generatorcontrolled circuits, wherein the electrical currents are generated by turning a crank manually and intermittently. The time intervals between successive current changes are usually substantially uniform throughout the integer signal but this is not essential; as will appear hereinafter, considerable variations in the durations of the individual impulses or interruptions of the current can be tolerated because it is the number and not the lengths of the impulses or interruptions that determines the integer. Individual integer signals Within a composite code are separated by pauses which are longer than the intervals between current changes within a single integer signal.

The invention is applicable both to closed type circuit operation and to open type circuit operation. In the former the circuit is closed and energized prior to the transmission of a signal (either continuously or only immediately prior to a transmission) and also during the pauses between successive integer signals of a composite code group, and the current changes are eiTected by opening the circuit or otherwise reducing the voltage to decrease the current flow a number of times depending upon the integer. Such changes are herein referred. to as interruptions, although the flow of current may not cease completely. In the latter operation, the circuit is open or de-energized or carries only a small current prior to the transmission of a signal and during the pauses between integer signals, and each integer signal is transmitted by applying a succession of electrical impulses to the circuit to create or increase the current flow a number of times. Although either type of operation may be employed in most installations, closed circuit operation is more commonly used with dial telephone equipment having a central source of electrical power and open circuit operation is more commonly used in telephone systems utilizing magneto generators and in radio networks wherein the current changes are effected by intermittently modulating a radio frequency carrier wave or by intermittently a continuous wave.

The permutations of integers of even reasonably low values, taken two or three at a time, are sufiiciently numerous to afford a great many different codes. For example, 9,261 dififerent codes are possible by combining three integers not exceeding the value twenty. However, in prior receiving instruments only a limited number of these codes could be usefully employed for selectively actuating receivers connected to a common transmitter because the selector mecha nism were such as to respond to more than one code. In my copending patent application Ser. No. 86,250, filed April 8, 1949, I have disclosed an improved selective signal receiver wherein the possibility of response to more than one code group can be obviated and a full utilization of the possible permutations of integers is possible in assigning codes.

The present invention is directed to further improvements in such devices and has for a general object the provision of a selector which has fewer parts and is simpler to construct and service. Further objects are to arrange the parts so that the mechanism will operate elliciently without delicate adjustment and is rugged and better adapted for use in mobile equipment.

In the embodiments disclosed in the aforesaid prior patent application a serrated or toothed code plate was advanced step-by-step from an initial position against the force of a spring by a propelling pawl which was reciprocated a number of times in accordance with the number of cycles of current change in the signal and the mechanism was arranged to make the first propelling stroke of the pawl in each integer signal longer than the subsequent strokes of the same integer signal. The plate was provided with one or more blocking deflectors at various blocked positions on the plate for preventing the propelling pawl from entering the serrations when one of these deflectors was opposite the propelling pawl, and the blocked positions were located to be opposite the pawl whenever one more than the correct number of strokes had been made by the aw its propelling pawl; this prevented the plate from being advanced more than one step beyond the position corresponding to the reception of the correet integer signal, regardless of the value of the integer signer 'At the end of a correct integer signal the plate was, therefore, brought to rest with the propelling pawl opposite a point one step short of a blocked position on the plate, so that the pawl was able reenter a's'er'ration upon making the first stroke of the next "integer signal; because this first stroke was longer than the others it advanced the plate-sufficiently to move the blocked position past the pawl thereby permitting subsequent strokes of the pawl in the said next signal to be "efiective forcontinued stepwise advancement of the plate. The plate was provided with "a retaining pawl for holding the p'l'a't'e in an advanced position after each propellihg'stroke and the retaining pawlwa's released at the end "of each integer signal to free the 'plateror'return to its starting position except when the plate was, at the endo'f such signal, advanced exactlyto one of severalprede'termined positions.

Now in accordance with thepre's'entinveh'tion it was'f'ound that-the operation and construction of'su'ch devices can be simplified and improved and th'at few'er parts can be employed by using the Ipropelling pawl only (for advancing the code plate up "to or forwardly from the blocked positions, i. e. without moving the plate-past a blocked position, andprovidi'ng an auxiliary drivingmemher for advancing the code plate past such blocked position when a correctfiriteger signal was received. As a resul't of this arrangement the successive strokes of the propelling p'awl may be of equal lengths and the plate may be advanced in equal steps, thereby simplifying the-construction of the'pa'wl actuating mechanism; it is evident, however, that the instant invention'is also adapted for operation with strokes of unequal lengths, as in the earlier device. The-auxiliary driving member need not perform the function of advancing the code plate after the completion of the'last integer signal of a code group particularly when, as in one of the embodiments to be described, the blocking means is omitted 'from the part of the plate which is near the propelling pawlat the completionofthecode group. The omission of this final blockingmeans and of the last operation of the auxiliary driving member are,-o f course, optional. v

In this specification frequentreferenceis made to various positions of the plate and positions on the plate. With regard to positions of the plate, any position to which -the plate is ad;-

vanced when the propelling pawl hascompleted the correct number of propelling-strokes within any integer signalcorresponding to the'construction or'adjustment of the plate, is designated as an A position; thus, there areas many A positions as there are integer signals in the comfposite'code. Thepositions of theplate in which the prepeningpam is ineffective to advance the plate are designated "as blocked or 3' positions;

there is a B"p'osition beyond every "A,"excep't that there 'need be no B positien "for 'the last bya distance equal to on'est'ep of the plate (usually e'qual'to one tooth interval), to limit the extent to which the'plate" will override: the A position "when too great an' integer signal is received, al-

though other spacings between the A alia B positions may be used. The positions to which the plate is advanced by the auxiliary driving member are designated as the C positions; it follows thateach C position is beyond a corresponding -A position by a distance equal to the advance of the plate caused by one operation of the auxiliary member. Each C position is, of course, beyond the corresponding B position. The distance between the A and C positions is usually greater than the length of the steps efiected by the propellingpawl, although the invention is not limited to any specific length for thestep caused by the auxiliary driving memher, the only requirement being that the plate be advanced beyond the blocked position to .perinit the propelling pawl "once again toenter the serrations and advance thecode plate when a subsequent integer signal is received. As regards positions-on the plate, the sam'e l'etters designate positions "which are opposite the propelling pawl at "the corresponding positions of the plate.

Any suitable blocking means may be provided for rendering the propelling pawl ineffective at each B position of thepl'ate. I Lprefer'to prov'idebl'ockingmeans on theplate itself atthe various B po'sitions thereon. These means may fta'ke the form of caps fitted with defiectors coveringthefa'ce of one or'more'teeth or'serrations, which caps' may 'be either permanently or adjustably mounted on the plate; or the blocking means may take the form 'of smooth portions separating-group's of teeth or serrations. Both of these types "are described in the aforesaid "patent application.

A "retaining pawl is provided for holding the fplat'ein"advancediposition againstthe force of a biasing force, e. ig.,'a springurg'ing the plate for retrograde movement to a starting or initial position. The retaining pawl holds the plate after each forward step of thepla'te caused'by a 'stroke'of the'propelling pawl, and'ma'y optionally 'als'b'hold theplate after an advancement caused by theauxiliary driving member. A mechanism ispro'vide'd for releasing thepawl at'the completion'of each integer signal to free the plate for return to thest'arting position at least'whenth'e piate-wasnot advanced exactl'yto "an A position; the pawl need" not be released when'the A position was 'ieache'd, "although release of the pawlin this'instance would, in them'ech'anism to be described hereinafter, not be objectionable because the auxiliary driving'memb'er itself engages the'pl a'te and moves it to a C position and then holds it there until the next integer signal causesfurthe'radvance of thelplate. It is evident that theplate -will be'returned'to starting position whenever the'iriteg'er signal-is too small or -'too f great to advance the' plate exactly to an "A.position.

At'the completion of the'last integer signal of a composite code theplate is in the final A position, which may according to one "embodifment, be the ultimate or'operati'ng' position of the plate; according to another embodiment the auxiliary driving "mechanism advances the plate beyond thela'st' A position 'to a final C positionj'which then is the'ultimateposition. In the ultimate position the 'plate is in condition to close an electrical contact or to actuate some other mechanical device for performing its signalling function. In'thepreferred embodiment to be dscribedythis final signalling is effected by "closing 'a'switch having two contact elements: One element is a'ipin'on'thelplate 'and the other is moved ac'r'os'sthe path of the pin at the completion of each integer signal so as to strike the pin only when the plate is stopped in the correct ultimate position. An optional feature, also shown inthe illustrated embodiment, involves retaining the plate in the ultimate position for an extended period of time by preventing release of the retaining pawl when the switch elements come into engagement. The plate is thereafter returned to starting position by transmitting one additional current impulse or interruption, which releases the retaining pawl.

While the device is particularly designed for operation with composite codes containing a plurality of integer signals it is also useful for operation with single integer signals.

The motors for actuating the propelling pawl and the auxiliary driving member may be of any suitable type and the mechanisms described above are not restricted to any specific arrangements. I prefer to make use of electromagnetic devices of the type indicated in the aforesaid patent application, which comprise a fast-acting armature connected to the propelling pawl for reciprocating the pawl in synohronism with the changes in the electrical current, and a slowacting armature connected to the auxiliary driving member and to the retaining pawl to move these elements at the completion of each integer signal or at a short time after completion thereof.

Having thus indicated the general nature and objects of the invention, the best mode of applying the principle will be described by reference to the drawings forming a part of the specification and illustrating certain preferred embodiments by way of example and not by way of limitation, wherein:

Fig. l is a diagrammatic plan view of a selector with the armatures in positions assumed during the reception of an integer signal, the operation being of the open circuit type;

Fig. 2 is a fragmentary view of the selector of Fig. 1 showing action when an incorrect signal was received;

Fig. 3 is a view similar to Fig. 2 showing the action when a correct signal was received;

Fig. 4 is a voltage diagram illustrating the signal used to actuate the selector of Fig. 1;

Fig. 5 is a diagrammatic plan view of a modified form of selector suitable for closed circuit type operation;

Fig. 6 is a voltage diagram illustrating the signal used to actuate the selector of Fig. 5;

Fig. 7 is a circuit diagram for a modified transmitting station suitable for the embodiment shown in Fig. 5;

Fig. 8 is a plan view of a selector suitable for open circuit type operation;

Fig. 9 is a front elevation view;

Fig. 10 is a horizontal sectional View taken on line Iii-4i] of Fig. 9;

Fig. 11 is a sectional view taken on line llll of Fig. 8;

Figs. 12 and 13 are enlarged side and end views of a cap for blocking the plate; and

Fig. 14 is a plan View of parts of the mechanism with the code plate removed.

A. Description of first embodimentFigs. 1-4

Referring particularly to Fig. 1, the selector is illustrated diagrammatically and parts have been spread out substantially in one plane to facilitate ready comprehension of the principle involved, it being understood that in an actual device the parts would be more closely assembled in the manner of the actual device illustrated in Figs. 8-14. The device has a support table plate 20 on which the code plate 2! is translatable, guided by four guide rollers 22. The plate is urged to a starting position toward the right by a spring 23; in the starting position shoulder 2 3 on the code plate engages stationary pin 25 which is carried by the table plate 20. The upper edge of the plate is serrated to provide a series of teeth '25. A retaining pawl 2i is pivotally mounted on plate 25 and urged toward counterclockwise motion by a spring 28 for holding the plate in advanced position (to the left from starting position) by engagement with the teeth thereof.

The plate is advanced toward the left stepwise by a propelling pawl 29 the left end of which is bent upwards and adapted to enter the notches between the teeth successively. The pawl 2t lies between the plate 2il and pawl 2? and is pivotally mounted at 33 on an extension 35 of an armature 32 and is urged against the edge of the code plate by a spring 33. The main part of the armature cooperates with an electro-magnet having a core 24, a solenoid winding 35, and magnetically permeable plates 35 and Bi. A brack t on the plate 3'1 affords a pivotal support for the armature, which is normally positioned in non-attracted position by a spring 33, with the propelling pawl retracted in the position shown in solid lines; this moves the arm 3! against a fixed stop pin 39 to limit the retraction stroke of the propelling pawl. When the winding 35 is energized a magnetic circuit is established through the core 34, the plates 38 and El, bracket and the armature 32, thereby attracting the latter to the dotted line position and moving the propelling pawl to the left. This advances the code plate one step (equal to one tooth interval) to the left when the pawl 29 is engaged with a tooth at the beginning of the stroke. Immediately upon the cessation of the current in the winding the magnetic field collapses and the armature is returned by its spring 38 to the solid line position, thereby retracting the propelling pawl. Pawl 2? holds the plate advanced when pawl 29 is retracted. The armature is, therefore, a fast acting armature which moves in synchronism with current changes in the winding.

The code plate carries three blocking deflectors 40a, iii?) and 460; they are located at the three B positions, as previously defined. The third deflector is optional and may be omitted or even located beyond the third C position, merely to prevent the code plate from being advanced too far beyond the ultimate position. fhese deflectors have the parts thereof near the teeth offset upwardly from the code plate so as not to interfere with the action of the retaining pawl 2?. These parts span one notch between teeth and the edges thereof are engaged by the upturned left end of the propelling pawl to prevent entry thereof into the blocked notches. When the plate is positioned with one of the blocking deflectors op-- posite the left end of the pawl 29 when the latter is retracted, the pawl slides over the deflector without advancing the plate when. the armature 32 is attracted.

The code plate is shown set to receive a code consisting of the integers 412, i. e., having a sequence of integer signals containing five, two and three current impulses, respectively; the reason for the extra impulses will be explained later. It will be noted that there are five notches between the left end of the serrations and the first deflector ita, which blocks the sixth notch;

43in reach :of athethree A positionsof the plate 24 when the member =43 .is .in its normal position against the stop "pin= M. .This -.driving; memher .is disposed below the ,plate '21 .and the toe 52 extends upwards toward the plate. The drivlug-member is afforded pivotal support-by .pinAS .carriednearthe end cf an extension-cfiofa slowacting armature ll-which has a=pivotalsupportat 43 on a bracket 36a. The :membertii is urged to its normal position againstthe pin .44 by a spring as, the abutment and oneend oithe spring being secured to the plate 29. Thespring leper- 'forms a second iunctionofnrging the armature 3? toward its non-attracted position (shown .in solid lines in Fig. 2) against-a stoppinSEl. The

core of the electromagnet extends to-therightbeyond the transverse plate 3! to another transverse plate 5i of high-magnetic ,perineabilityand the part-oi thecore between plates 3? audit is surroundedrby-a'lug 52,-such asa ring of;conductive material, e. g., copper; thisluginfluences the magnetic :ilux in the part-of the care within the lug so that the flux breaks 1 down slowly after the winding 35 is 'de-energized. When this winding is energized a magnetic'circuit, in addition to that previously described, is established through the part -.of the core within the dug, the-plates 3'1 and 5!, and the-armature 4?, wherebythelatter is attracted totheposition shown-in Fig.1. When the electric currentzinthewinding is interrupted this magneticfield decays-slowly and the armature w ll remains attracted :for .a brief periods g., from a-quarterof .a second up to one second after thearmature BEisreleased. As a result of this slow-releaseaction the-armature cl will-be attracted during-the first electrical impulse'of an integersignaland .will not be .re-

leased in the intervalsbetween. consecutive, rapidly recurring impulses. It is, of course, .im-ma- .terial how long each. electrical impulseislheldand whether they be of .thesamedurations; the only requirement .is that the intervals during which the winding "35 is de-energizedlbe short enough to prevent release of the armature i'l to .thesolid line position shownin'Fig; 3.

The third pin 4 l c is electrically insulatedfrom the plate?! and is electrically connected-tea wire 53; it"iorms one contact element of anelectrical switch, the other element of which is the toe &2 of the driving member '43. The latter-is-grounded to the plate'ill'to which a wire cd -is-'connected.

.isreleased to the position .ofgllig. Zit will engage :the side of the propelling pawl;and;=.push:.it away .from thecodezplateizi. .lIt will bemoted .that the retaining .pawl 2i ihas aniextensioncfiddisposed Thedriving .niem- .ber is of 'suchlength thatzwhenthe. armature ill away :from the plate .2! and that theaupturned end of the propelling pawl moves :between this extension and -plate 2!. When the slow-acting armature 47 is .released and the driving toe .82 does .not engage one :of the ;pins ilaike .the driving member 43 .moves upwards, sliding. along .theabutment pinc' l under the influence of the spring A9 and the heel 5T pushes the propelling pawl away from the serrations on the plate .24; this pawl, in turn, engages the extension "1518 of the retaining pawl, thereby rotating the latter away :from the serrations rand Ifreeing the plate 2| to return toward -.the..rightundertheinfluence of its aspring'23 to its-starting position. When, however, the toe-d2 alignment withone *oi the pins tic-filo v(i. e when the plate 2| :is in an A positiom atthe time-that thesloweacting armature is released, thedriving member engages the-pin in question and advances theplateztoward .theleit-to'the next C position. zln-this connection-it should be noted that the line joining the teed? and the pivot pin i'5'is:n0t:perpendicular to thendirection'of travel of the plate 2-! "butislinclined with the toe i2 displaced in the direction of the forwardtadvance oi the plate. Because ofthis the driving member urges :the plate toward the left when the .sioweacting armature .is released and pivots'in. a clockwise .directi-onabout its :"PlVOl? 33. In thus .advancingthe platethe drivingmemher &3 also pivotsaboutpivot pin tiland moves away from the abutment :pin strand against .an abutmentpinb :whichlimits the advance of the plate toadistance of two toothed intervals; the heelill isthereby moved ahead ofthe propelling pawlso that the propelling pawl andretaining pawl are not engaged thereby but remain engaged with thecode plate.

The winding'tfi has'its terminals 68 and fil connectedtothe line 62 leading to a transmitting station indicated diagrammatically at T. This station may have any suitable means for transmitting a-eode such as, for example, an-electric battery 63 connected to a normally open-switch fid which is automatically closed when a telephone receiver is removed from its support, and a normally-opendial-controlled switch 65 which will close the "circuit in rapid succession a "number of times-in accordance withthe integer position to which the dial ofdial= mechanism 66 is rotated prior to release. The dial is constructed to close the switch a number of-timeswvhichexceeds-by one the number of the integer, and the digit 0 is=transmittedby closing theswitch-eleven times.

B. Operation of the first embodiment The correct codeifor this platelet-1142. The device is initially de-energized and'the. codeplate 2| is in its starting :position at the sright, with shoulder 24 .in engagement with .pin :25 and the propelling pawl 29 and retaining pawl away from the platelZ l When the receiverat the transmitting station T is lifted switch 64 is closed but the iline=fi2 :remains :de-energized, :as indicated at a in Fig. 4. The dial -is -.then-turne.d*to the first number of the code. andreleased; .onathe return of the dial it .clcses the switch Ed ;a number-..of times equal to the said number plus one. Thus, in the example here illustrated, the first integer "oftthecode is 43; hencewhen 4. is dialled-a there :wilLbe five impulses,.as shown between pointsrb andein-Fig. 4. 'Whenthefirst .of thesezimpulses isreceived at the winding .65 'both armatures .32 .andsliil are attracted, causingthe propeilin pawl 329 to make a. stroke totheleft (totherdottediline position) .and :retracting the auxiliary .driving member 43. The propelling pawl was, however, initially away from the serrations of the plate 2 I, so that the plate is not advanced during the first stroke. At the end of the first stroke the retaining pawl 21 is in operative position against the plate 2|. When the current is interrupted following the first impulse the armature 32 is released and the pawl 29 moves back to the right and there enters the first notch oi the plate 2|. The second impulse occurs before the magnetic field acting on armature 4'! decays sufiiciently to permit release of this armature; the propelling pawl thereupon make a propelling stroke and advances the plate 2| one step to the left, where it is retained by the pawl 21 when the propelling pawl is retracted following the completion of the second impulse. The plate is, accordingly, during the transmission of the first integer signal, advanced a number of steps one less than the number of current impulses transmitted, i. e., a number of steps equal to the integer transmitted (reckon-- ing zero as having a value of ten), except that, as is explained below, the plate cannot be advanced beyond the B position.

Fig. 2 illustrates the effect of transmitting an integer signal which is too small, i. e., one which advances the plate only to a position in advance of its first A position. Assuming the integer 3 to have been received, at the cessation of the last impulse of the signal the plate is advanced three steps to the Fig. 2 position and, shortly after release of the armature 32 and retraction of the propelling pawl, the slow-acting armature 41 is released under the influence of the spring 49. This pushes the driving member 43 upwards and brings the heel 51 into engagement with the pawl 29, pushing it away from the plate 2|. The pawl 29 in turn, engages the extension 58 of the retaining pawl to rotate the latter away from the code plate and permitting the latter to return to starting position under the force of its spring 23.

In the event that too great an integer is transmitted the plate is advanced to a position one step beyond its first A position, to the first B position, with the first deflector 40a opposite the end of the propelling pawl. Additional strokes of the pawl are ineiiective to advance the plate beyond the B position because the end of the pawl cannot enter the notch between the teeth; hence the plate can be advanced only to the B position, regardless of how great an integer signal is transmitted. At the end of such an integer signal the slow-acting armature is again released and the plate is returned to starting position by the operations described in the foregoing paragraph.

Fig. 3 illustrate the eiTect of transmitting the correct integer signal, i. e., one which advances the plate exactly to the first A position, shown in dotted lines, with the first pin 4 l a in alignment with the toe d2 of the auxiliary driving member it. When the slow-acting armature 41 is released the driving toe A12 engages the pin 41a and pushes the plate toward the left to the first C position, as indicated in solid lines. In this movement the member 43 rotates counter-clockwise about its pivot pin leaving the abutment pin i l and causing the heel El thereof to move out of alignment with the pawl 29. As a consequence the latter is not raised from the plate and the retaining pawl 2'! remains in operative position. The member 43 engages abutment pin 59 at the end of this driving stroke. In thus advancing to the C position the plate moves past its first 13 position, i. e., the deflector 42a is moved past 10 the end of the propelling pawl, so that the latter is in position to advance the plate when making the next stroke.

When the second integer signal is transmitted the events described above are repeated, with the difierence that the propelling pawl, being now already in engagement with a notch in the plate 2 l, advances the plate already with the first stroke; hence the plate is, in all integer signals subsequent to the first, advanced by a number of steps equal to the number of current impulses, or one step more than the integer transmitted (reckoning the integer zero as ten), except that it cannot be advanced beyond a B position. The second integer signal is indicated between it and e, and the third signal between points 7 and and 9, Fig. 4.

At the end of the third integer signal, assuming that all three integer signals were correctly transmitted, the driving member 43 engages the third pin Mo, thereby closing the signal circuit through the battery to operate the signal device 56, and simultaneously advancing the plate to the last C position.

The plate 2| may then be returned to starting position by applying any signal, preferably one or two impulses, to the winding 35. Such impulse may be generated at the transmitting station T by dialing the integer one, or by any suitable circuit at the receiving station where the selective signal device is located e. g., automatically when the receiver is lifted from its support. Since such circuit for providing a single impulse to the winding after the station is called is not a part of the invention and the design thereof is well within the skill of persons versed in the art, it will not be further described.

C. Description of second embodiment, Figs. 5, 6' and 7 The embodiment illustrated in Fig. 5 uses a rotating disc for the code plate and is designed for closed circuit type operation, using a signal generator of either of the types illustrated in Figs. 5 and '7. Another feature of this embodiment is the provision of a slow-acting armature which acts far more slowly than that according to the other embodiments, making the device particularly suitable for use in installations using hand-operated magneto generator. In such installations the successive current changes within each integer signal are brought about by turning the generator crank a number of times in succession in accordance with a predetermined code, and each interruption or impulse may have a duration of from one to several secondswhich is longer than the decay time of a magnet using a lug of the type previously described if a magnet of reasonable size is to be used. While this special form of slow-acting armature is disclosed in connection with this second embodiment-the only embodiment intended for closed circuit type operation--it is evident that closed circuit operations may also be used with slow-acting armatures using lugs, a suitable arrangement therefor being, for example, described in the aforesaid prior patent application.

Referring to Fig. 5 in detail, there is shown a base plate 10 on which is fixed a vertical shaft H forming a journal for a rotatable, circular code plate 12 urged to rotate in a clockwise direction by a wound spring 13 to starting position; in the starting position a pin 14 on the lower side of the plate is in engagement with an abutment mounted on the base plate. The drawing shows the code plate rotated ten steps to counterclockwise. The code plate hasperipheral, equally spaced teeth it; The teeth; as shown, are not symmetrical about radiito-the centerof the code-plate, so as" to facilitate: driving engagement therewith of the" propelling pawl in a counter clockwise direction while permitting: the pawl to slide over the teeth. on the retraction stroke thereof; Two blocking deflectors Na, and iil h'ane'mountedon the plate at angular. position corresponding to the first two B positions on the plate; these deflectors. are constructed; as previously" described for the deflectors sea-40c and arer secured to' the plate by screws 781i and tab;.respectively,fthreadedly fixed in tapped holes in: the:- plate: and". extending: beneath: the plate" for cooperation with: the auxiliary driving" member.

A retaining pawl i9 is pivotally mounted on a pin ea carried by the base plate and is shaped to engage th'e' teeth T6 in succession, being urged counter cloclwise by" a' spr i'n'g' 81 to engage the c'ode late. A: vertical in 82 carried by the pawrestenesboth above and beneath the awl; The: propelling pawl 831s in the form of a circular rod having the main, horizontal part at the let el of the upperpart or the pin 82 having the endsflt and 85 thereof" turned u The latter 'e'r'id is pivotally supported at the end of an arm 86 oft-hefast acting armature 81 and the front end 85 is disposed to engagethe teeth of the cedeplate and to extend to above the height of the blocking deflectors Fla and 11b so asjto prevent driving engagement with the blocked notches when the plate is in one of the first two E positions, A spring acting counter-clockwise against" the code plate. The armature 31 is a.fi6rdedpivotal support by a pin 89 for cooperation with an electromagnet having a first core-"9 3 and twormagneticallvpermeable p ates at and 92; it is urged away from the magnet against a stop pin 93 by a spring 94. The core 90 carries a solenoid winding 95 which, when electrically energized, causes the armature to be attracted from the" dotted line position to the solid line position. 7

The auxiliary driving member 95 is located between the ba e and code plates and ispivotally supportedat 91a on the slow-acting armature 9'! which is,. in turn mounted on avertical pivot 98 'Iihisarmature is free to swing about its pivot between the lower end of the plate 9| and. a short extension 99 of a second corev l!!!) which is shown to be integral with the plate 921 A" spring Hi l, acting between apin I02 onthe base plate and. the auxiliary drivin member,

urgesthe latter clo kwise about point 91a a ainst an-- abutment pin i03- andalso urges the driving member to: pushthe armature 91 in a counterclockwise direction to the solid line position against the extension 99. A second abutment pinv Nita-- limits the pivotal movement of the driving member away from pin N33. The driving member has an upturned driving toe I04 which is shaped.- withv aconcave engaging face for engaging the lower, protruding ends of the screws 13w and. 18b when the code plate is in one of its A positions and the driving member is against the pin' tilir. The driving member further has a heel N35 with: a concave engaging face located toengage the lower end of the pin 82 of the retaining pawlwhen the driving member is against thepin' Hi3; The toe and heel" are clear of'thepi'ns 7821,1813 and 82 when the slow-acting armature is in its lldlfllell, Solid line position, tn any ermitting free rotation of the code-plate Either direction; but engages the appropriate pin: when the armature is rotated clockwise. The armature: 9i has'an arm: I06 extendinglbeyond the edge of: the code plate and having a vertical end It? rising: to above the code plate. A holding arm its is secured to the top of the end i'il'i and insulated electrically therefrom. The freeend' of the'holding arm extends over the code? plate and carries a depending contact and engaging pin ice. A pin H0 is fixed to the code plate: at an angulariposition. to be opposite the pin its when the code plate: is in. the third A position; and at a radial position. to move freely radially insideof thep'in H19 when the armature Sit is in its normal, solid" line position, and to move freely radially-outside of the pin I09 when the: armature is inthe dotted lineposition, against the plate 951. I'heradiallyinner face of the: pin !09' is flat or concave to insure contact with the pin Hi3 when the armature 91 moves in a clockwise direction.

The second core lflfl carri'es a solenoid winding Hit having less turns than and connected in series with. the Winding" 95 through a wire H2; The termini of. the windings remote from the wire m1 are connected by wires H3 and H4" to the'line H 5 which leads tothe'transmit'ting stati'onv Ii provided with any means for transmitting a: signal; such as; a hand-operated magneto gencrater. l' i'6.

The winding H I has its termini further connected by wires HT and H8 to opposite sides of a normally open, delayed-action switch H9 which. is mounted to the base plate by a bracket [2%. The switch has a pair of insulated resilient leaves I21, I22, carrying the contact elements 123, which are" normally separated by an insulated leafspring'i 12d. The leaf in carries a Weight [25 and the leaf l2! has an insulated abutment are positioned to be engaged by the 1 9 end of the arm 86 when the armature B1 is moved to its attracted, solid line position. It is evident that when the contacts [23' are together the winding HI is short-circuited by' the delayedactidnswit'ch; When the armature 8'! is released, in dotted line position, the arm 86 is away from the abutment l2 E- and the contacts I23 are separated by the action of spring l24. When the armature is attracted the arm 86 strikes the abutment i 25 the leaf l2! and spring I24 are flexed, bringing the contacts 23 together; this also flexes the leaf" [2 2 and the inertia of the weight 1 25 causes the latter leaf to move away from the arm 86 toopen the contacts. The weight [25 thus setsup a series of vibrations or oscillations; resulting in a series of momentary contacts between the contacts I23 until the oscillations are damped out. The winding HI is, therefore, not short-circuited by any sustained circuit until the vibrations cease, which may occur in from one to four seconds, depending upon the stifiness and length of the leaf I22 and the weight I25.

The local signal circuit comprises a battery l2? and bell I28 connected in series between ground and the insulated holding arm [08, the latter connectionbeing through a wire l29. The code plate is electrically connected to the pin H0 and to the base plate 10 which acts as the ground.

D. Operation of the second embodiment This device is suitable for various types of closed circuit operation, of which two will be illustrated. The circuit He may be de-energized prior to operating the device, as indicated at a, Fig; 6,. or it may be continuously energized; the

former situation is more common and will be described in detail. Initially, the code plate 12 is in starting position (extreme clockwise, with pin 14 engaging abutment l and the first tooth 16a opposite part 84 of the propelling pawl in the solid line position shown); the fast acting armature 8; is released with the propelling pawl 83 forward (and the part 85 thereof one step toward counter-clockwise of the first tooth 16a) in the dotted line position; the slow-acting armature 91 is in its normal or first position, shown in solid lines; and the contacts !23 of switch H9 are open.

(1) Magneto generator opcmtion.--It is preferable (although optional) to precede the transmission ofv the code by a long, preparatory impulse to insure that the code plate is returned to starting position following a subsequent operation. Such a preparatory signal, generated by cranking the generator M6 for two or more seconds, is indicated between points I) and d in Fig. 6; it energizes both windings es and ill, but at first causes only the former to be attracted (through a magnetic circuit including core 99, plates 91 and 92 and the armature 8'!) to the solid line position, thereby retracting the propelling pawl. The magnetic field of winding 5 also urges the slow-acting armature to the second, dotted line position against the plate 9|, but the magnetic field of the winding l l l, acting through the core Hit, extension 99, the armature ill and the lower part of plate 82 prevents movement because the armature is initially in this magnetic circuit and closer to extension 99 than to plate 9i. Movement of armature 8? causes its arm 86 to strike the insulated abutment 26 on leaf lZi, thereby momentarily closing the contacts 23 and setting the leaf I22 and its weight E25 into vibratory motion. Leaf I'll is maintained to the right by arm lit, with spring 524 flexed. While this motion persists the contacts US are repeated closed for short periods, insufiicient to short circuit the winding ill effectively. When the vibrations cease-which occurs in a matter of one to several seconds after movement of the arm 36, depending upon the characteristics of the leaf E22 and the weight, which may be selected as desired to suit the speed at which the signals are to be transmittedthe contacts I23 remain closed and winding III is continuously short circuited. This occurs at point 0, Fig. 6, and it should be noted that the preparatory signal bd is longer than the damping period bc of the switch. The magnetic field of the winding 95 is now unopposed and the slow-acting armature is attracted to its second position; this moves the auxiliary driving member 96 to bring the heel 35 into engagement with the lower end of pin 82 on the retaining pawl is and releasing the pawl from the code plate. In this movement the spring lcl maintains the driving member in sliding engagement with abutment pin H33 and the toe H14 of the driving member encounters no pin on the code plate. Movement of the retaining pawl causes the pin 82 thereof to engage the propelling pawl 83 to swing it about its pivot on the arm t6 away from the code plate. The plate is thereby freed to move to starting position in the event that it was not initially in such position. The first notch 16a is now opposite the end a l of the propelling pawl.

When the generator is stopped at point (1 both armatures are released, thereby retracting the auxiliary driving member, permitting spring 8| to move the retaining pawl against the code plate into operative position, opening switch I I9, and advancing the propelling pawl which is moved against the code plate by its spring 88. The latter, however, does not advance the code plate because it was, at the beginning of its stroke, away from the code plate; instead, it moves one step beyond the first notch 76a. The device is now ready to receive a code; when the optional preparatory impulse is omitted, the operation begins with the elements in this condition.

The code for this plate is 35-- i. The first integer signal is transmitted by operating the generator and making three interruptions, as indicated between points 6 and f, Fig. 6. (This may also be described as transmitting three short impulses.) The durations of the interruptions are of no importance; however, the impulses between interruptions should be shorter than the damping period of the vibrating switch, indicated from b to c. This last condition insures that the armature 9'! remains in its first position throughout the integer signal. When the windings are energized at point e fast acting armature Bl is attracted to its solid line position, thereby setting the vibrating switch in motion and moving the part 84 of the propelling pawl into the first notch 580.. During the first current interruption following point e the propelling pawl advances the code plate one step, and when the windings are again energized the propelling pawl is retracted and the switch is given another impulse to vibrate the leaf I22. This action is repeated until the plate has been advanced three steps. At time the code plate is in its first A position, with pin 18a is in alignment with the toe Hi l of the auxiliary driving member, and energization of winding at this time causes the propelling pawl to be retracted with the part 84 thereof in the notch immediately to counter-clockwise of the first blocking deflector Tia. The current is maintained between points ,1 and h for a time longer than the damping period of the switch, and when the switch stops vibrating at point g the slow-acting armature moves to its second position. This actuates the driving member 96 to engage the toe H14 with pin Ilia and advances the code plate until the driving member engages pin l93a, i. e., two steps, to its first C position, with the deflector Tia beyond the part 34 of the propelling pawl, permitting the latter to enter the first notch beyond the deflector. (This action is illustrated and described with reference to the second blocking deflector 'i'ib in the next paragraph.)

The second integer signal comprises five current interruptions occurring between points h and i. (This may also be described as transmitting four short electrical impulses.) When the current is first interrupted at h driving member 95 is retracted but the plate is retained in advanced position by the retaining pawl. Armature 37 is also released to advance the propelling pawl, thereby advancing the plate one step, it being noted in this instance the retaining and propel= ling pawls are already in engagement with the code plate when the first interruption occurs. At the end of five such interruptions the code plate is advanced five steps to its second A posi tion (ten steps from starting osition), which is the position shown in solid lines in the drawing, and when the steady current is resumed at 2' the propelling pawl moves into the notch immediately to the left of the second blocking deflector lib as. shown: in solid lines. When. the. switch stops vibrating at point 9'. the armature. ill; moves to second. position and the toe. IE4: or; the auxiliary driving member. 95! engages the pinv 'lB-b, thereby advancing the code. plate two. stepsto the dotted line position, which. is the second C position. Movement is again limited by engagement of the member 96 with thepin Ifita. As is shown inthe drawing, the part M is now." in. the first notch beyondzthe deflector Mb.

The third integer signal comprises four current interruptions occurring. between pointsv 7c and Z. The code plate isthereoy advanced four stepsby the operationsdescribed in the foregoing paragraph, to bringjtheplate toits third A position with: the pin Ii il in alignment with the pin I09, as shown in dotted. lines. When the switch stops vibrating, at a time indicated by point 7c, the armature 97E. starts to move to its second position, thereby swinging the holding arrn IE8 and pin iil radially in withrespect to the code plate. The pin ms: engages pin i it] after only a limited movement has occurred, thereby arresting completion of the movement of the armature and preventing the retaining pawl 79' from being moved to inoperative position. The code plate is, therefore, retained in its ultimate position which, in this embodiment, coincides with the third A position. It also establishes electrical contact between the insulated pin ltd and grounded pin Hi3, thereby closing the signal circuit through wire are, battery 42'! and bell I28.

To stop the local signal at the receiving station the transmitting signal is interrupted, as indicated at m, by any desired means thereby causing the propelling pawl to advance the code plate one step and moving the pin I'Iil away from pin 99. The device may be left in this condition, or a further long or ring off signal, indicated between points 72 and 12, may be transmitted; the latter will cause the auxiliary driving member to move at a time indicated by point to release the retaining pawl and permit the code plate to return to starting position, the pin H6 being free to pass radially outside of the pin Hi9.

Should either of the first two integer signals be smaller than those described above, the code plate would not be advanced to the A positions, and when the auxiliary driving member 96 is moved it would not encounter a pin 58a or 3%; hence it would slide along the pin I93, bringing its heel: 595' against the pin 82 and releasing the retaining pawl to return the plate to starting positionunder influence of spring it. Should either of these signals be too large, the plate would be advanced one step beyond the respective A position, into the corresponding B position; further advancement would be prevented by the corresponding blocking deflector, which prevents the entry of the part 84 of the pawl into a notch. At the end of such a larger signal the auxiliary driving member would similarly move the retaining pawl to permit the plate toreturnto starting position. Should the third integer signal be either too small or too large the pin IIB. would not be aligned with the pin Iiiitand the stroke of the slow-acting armature at point It would not be arrested; the auxiliary driving member would, therefore, again engage the pin 82 and move the retaining pawl to permit return of the code plate to starting position.

(2) Dial operation-The device of Fig. may also be operated by a dial at the transmitting station, as shown in Fig. '7. In this instance the transmitting station comprises a battery 63, a

normallyopentelephone receiver actuatediswitch 6d, a. normally closed, dial-controlled, switch: 65c, connected in series with the. line circuit H5; Switch 650.. is actuated by a dial mechanism 55a to open the circuit asuccession of times equal. to the integer, the integer 0 being transmitted by ten interruptions. The code for this device, when controlled by the transmitting stationof Fig. 7, is: 4=.-54, and Fig. 6 again represents the operation. It. is evident that a switch. H9 having a shorter damping period would be used in this instance.

The circuit I I5 is initially de-energized, asindicated at. a, Fig. 6'. When the receiver at the transmitting station is lifted switch 64 is closed and a. steady potential is applied to line H5, as indicated at b, Fig. 6. When thenumber 4 is dialled the current is interrupted four times, be.- tween pointsd and: I; subsequent dialling. of 5. and 4 causes five and four interruptions, between points it and 2' and between points It and i, respectively. The action taking place at the receiver is that previously described. with reference to magneto operation.

E. Description of'thz'rd embodiment-Figs. 8 to 14 The selector shown in Figs. 8 to 14 is adapted for open circuit type operation. It comprises a bed plate 93!! of non-conductive and non-mag.- netic material, such as plastic, to which a laminated magnet core It! is secured. by means of screws engaging transverse plates 5,32 and I33 at the ends. These plates, as well as intermediate plate lfi i, are made of material having high magnetic permeability. A solenoid winding I 35 surrounds. the core, between the plates !33 and lad, and a. lug 535 of conductive material surrounds the part of thecore between the plates I 32 and: I34. The winding I35 is energized by a circuit I37 connected to. a transmitting station T having. any suitable means for transmitting the code, such as an electric battery I38 connected through normally open switches I39 and I40 to the circuit. Switch 539 is closed whenever the receiver is removed from its support, and the switch I is closed by the dial mechanism MI in the manner previously described for the first embodiment, e. g., to close the circuit in rapid succession a number of times exceeding by one the value of the integer being transmitted, the integer zero being transmitted by eleven impulses.

The fast-acting armature M2 is in the form of a plate mounted on a vertical hinge pivot I83 supported by the plate I34 and urged in a clockwise direction by a leaf spring Edd against a stop 5 35 which is, in turn, carried by an extension Itfia'of the plate I33. When the winding I35 is energized a magnetic circuit is established through the core I3I, the plates I33 and I34 and the armature I i-2 to move the armature in a counter-clockwise direction. The armature is released and moves in a clockwise direction immediately upon de-energization of the winding. The slow-acting armature I 36 is in the form of a plate mounted on a horizontal hinge pivot I41 near the bottom of the magnet and carried by the end plates E32 and I 33. It is urged by a leaf spring M3 to a position away from the magnet. When the winding I35 is energized magnetic circuits are established through the core I3I, the plates E33 and ISG, and the. armature bib; and also through the core, the plates I32 and I34 and the armature, thereby attracting the armature. When the winding I35 is energized the armature is attracted; when it is ole-energized the decay of the magnetic flux through the latter circuit is delayed by the action of the lug I36 and the armature does not move away from the magnet until a short time of the order of half a second has elapsed.

A table plate I49 is mounted on the top of the magnet by screws. It carries a vertical shaft I50 forming a journal for the code plate II which is urged in a clockwise direction by a coiled spring I52 to starting position, with pin I53 on the plate in engagement with stationary abutment pin I545 on the table plate I d6. The code plate has teeth I55 at its periphery and a ring of internally threaded holes I56 located radially inward from the respective teeth. A retaining pawl I51 is pivotally mounted on a vertical post I58 which is mounted on the plate I46 and carries a coiled spring I59 urging the pawl in counter-clockwise direction against the code plate for holding the latter in advanced position after the plate has been advanced.

An arm I 66 is ragidly secured to the top of the fast-acting armature and extends diagonally under the code plate to the point I6I, at which it is bent upwardly. The propelling pawl I62 extends beneath the code plate and has the ends thereof bent upwardly; one end receives pivotal support in the end of the arm I6!) at I6I. A coiled spring 563 urges the pawl in a clockwise direction with respect to the arm I66 and urges the other end I64 of the pawl against the code plate.

Movement of the slow-acting armatur I 46 away from the magnet is limited by a stop I65 which is secured to the plate I46. A bracket I66 is secured to the top of thi armature and has the top thereof bent to extend horizontally between the plates I49 and ISI for movement together with the armature. The auxiliary driving LL member I61 is pivotally mounted to the bracket I66 about a vertical pivot I68 and is urged in a clockwise direction by means of a spring I69 against an upstanding lug I16 which is integral with the bracket. This driving member has an upright toe Ill formed with a slightly concave engaging surface directed radially outwardly with respect to the code plate for engaging pins depending from the plate, to be described. The driving member further has a heel I12 positioned to engage the retaining pawl I51 to move it away from the code plate when the slow-acting armature, bracket I66 and driving member are moved away from the magnet with the driving member I61 in the illustrated position in engagement with the lug Ill). The driving member further has a part thereof formed as a curved cam surface I13 disposed to engage the radially inner side of the end I64 of the propelling pawl. This surface pushes the propelling pawl away from the code plate when the armature, bracket and driving member are moved away from the magnet with the driving member I61 in the illustrated position. Both the heel I12 and the part providing the cam surface I13 are narrow, whereby they are clear of the retaining pawl I51 and of the propelling pawl, respectively, when the driving member is rotated in a counter-clockwise direction, away from the lug I16.

A post Il l is optionally mounted on the plate I49 to limit the propelling stroke of the propelling pawl.

Two blocking deflectors HM and I151) are mounted on the code plate. These deflectors are shown in detail in Figs. 11 to 13 and have lower horizontal portions I16 restinglon the upper face of the code plate; upright portions I11; and upper horizontal portions I18. The latter have the edges thereof which are radially outward with respect to the code plate disposed at about the maximum diameter of the code plate so as to prevent the entry of the vertical part 964 of the propelling pawl into the notches between the teeth at the blocked positions on the plate. Because the upper portions IlS are elevated above the code plate they do not interfere with the action of the retaining pawl I51, which is low enough to enter the notches beneath the deflector. The lower portions I16 have holes through which screws 519a or I161) extend, these screws being threadedly secured in selected holes I56 in accordance with the code to which the plate is adjusted and extending beneath the code plate to form pins for cooperation with the toe I1I of the auxiliary driving member. The driving member E61 is located circumferentially with respect to the shaft I56 to have the toe I'll thereof in alignment with one of these screws in each of the first two A positions of the code plate. It will be noted that in this embodiment only two deflectors are provided, i. e., the plate has only two blocked B positions. However, the device is intended for the reception of a code consisting of three integer signals, and a third pin I extending upwardly above the code plate is threadedly mounted in an appropriate hole I56 to complete th final operation of the device in a manner to be described. Should the selected code be such that the pin 189 is in a hole already occupied by a screw I 19a or I192), the screw is replaced by a longer screw which extends above the code plate to function also as the third pin.

A bracket ml is rigidly mounted on the slowacting armature and electrically insulated therefrom. This bracket has a horizontal part I62 and a downturned part I83 forming one element of an electrical contact as well as a movable abutment cooperating with the pin I66. The part I83 is radially within the circular path of the pin I86 when the armature M26 is in it attracted position and radially outside of the path when the armature is released. The pin I86 is located circumferentially on the code plate so as to be opposite to the part I83 when the code plate is in the final A position, i. e., the A position corresponding to the third correct integer signal. When the code plate is in this position at the end of the third integer signal, the part I83 engage the pin I80 during the first part of the outward movement of the slow-acting armature I46 and arrest further movement of the armature away from the magnet. This, in turn, prevents the bracket I66 and auxiliary driving member I61 from moving out to release and push the pawls I51 and I62 away from the code plate. The code plate is thereby retained in its ultimate position which, in this embodiment, coincides with the last A position.

The bracket I8I is electrically connected to a wire I84 which may be connected to any suitable signal device, such as a bell I85. The pin I86 is grounded to the selector and the frame of the latter is connected through a wire I86 and battery I81 to the signal device. It is evident that when the part E83 engages the pin I86 the signal circuit is closed to operate the signal device.

F. Operation of the third embodiment The third embodiment is shown in the drawings to be set to respond to the code 4-3-6,

transmitted as a-series of current impulses. of the type illustrated, in Fig. 4.. When switch I39 is closed and the first integer "4 is dialled in the mechanism I4I the switch I46, is, closed five times and; fl-ve electrical impulses are transmitted over the. circuit. I31 and the winding I35 is energized five times in rapid. succession. During the first impulse the armatures I42 and [46 are both attracted and the propellingv pawl makes a forward stroke. However, during the first stroke the cam surface I13 prevents, engagement of the part I64 of. the propelling pawl I62 with. the teeth of the code plate, and the plate is not advanced. At-

traction of the armature I46 causes the auxiliary driving member I61: to move'radially; inwardly to permit the retaining pawl I51 to move to operative position; it thereby also retracts. the cam surface, I13 and permits. the propelling pawl to engage the teeth. vThe four intervals'between the five impulses are of such short durations that the slow-acting armature I46 remains attracted until a short time after the; completion of the last. impulse because of the lug I36 the fastacting; armature I42, however, moves in synchronism with the pulses. As a result the propelling pawl makes a. total of five reciprocations and advances the code. plate one step. in. each of the four strokes subsequent to the first stroke; this moves the plate to the first A position, with the end I64 of the propelling. pawl inthe notch immediately ahead of the first blocking deflector I15a when the pawl is retracted at the end of the fifth impulse.

After the fifth impulse the current is interrupted for a time sufficient to release the armature I46, which moves into. engagement with the stop I65. This movement carries the bracket I66 and auxiliary driving member I61 radially outward with respect to the plate toward the position shown in the drawings. In the early part of this outward movement the toe I1I- of the driving member engages the firstv depending engaging pin I19a. Because the line from the pivot I68 to the toe MI is inclined: toward counter-clockwise with respect. tothe radius through the pivot, continued outward movement causes the driving member I61; to. turn in a counter-clockwise direction about its pivot I68 to advance the code plate two steps, past the first B position and to. the first. C position. As a result of this turning of the driving member the heel H12 thereof is swung, to counter-clockwise of the retaining pawl I51, whereby the latter is not engaged but remains in operative position against the plate. Similarly, the camsurface I13 is moved clear of the end I64 of the propelling pawl, whereby the latter remains. in engagement with the code plate during the advancement of the latter and the end I64 enters the first notch in the-plate beyond the first blocking deflector I15a.

When the second integer 3 is dialled four electrical impulses are transmitted. and the ac.- tion. described abovefor the first integer is repeated with the difference that; the; plate is advanced already with thefirstimpulse becausethe propelling. pawl. is initially. in engagement. with the code. plate. When the armature I46; is. at,- tracted at. the beginning of the. first impulse the auxiliary driving member I61 is retracted from the pin. H911 and is rotated clockwise by its spring I69 against lug I10, thereby assuming the position it had during the transmission of the. first integer signal. Thecodeplate'is, therefore, advanced four steps to thesecond A posi- *0 a tion during the. transmission of" the. signal, and

is further advanced two steps to the second C position by the auxiliary driving member which engages the secondv contact pin I19b. during the pause which follows this signal.

When the third integer 6 is dialled seven electrical impulses. are transmittedv and the action described in the foregoing paragraph is repeated: up to the point where the impulses end and the plate has been advanced seven steps to the third, A position. This position is, in this embodiment, identical with. the; ultimate position. After the last impulse is completed and the fastacting armature is released the slow-acting armature is released, but the auxiliary driving member does not encounter any depending pin and does not advance the plate. Instead, the downturned part I83of the bracket I8I strikes the radially innerside of the third pin- I88, which is now opposite. the bracket, thereby preventing completion of the-outward movement of the slowacting armature. This prevents the heel I12 of the auxiliary driving member from striking the retaining pawl. I51, whereby the code plate is retained in the ultimate position. Engagement ofv the pin I88 closes the electrical local signal circuit which includes. the insulated bracket I8I, wire I84, bell I85, battery I81, wire I86 and the grounded pin I80.

To return the code plate to starting position any signal, such as a single or a pair of impulses, which may be generated at the transmitting or at the receiving station, is applied to the winding; this attracts the armature I46 to retract part I 83 from the pin I and advances the code plate one or two steps, respectively, beyond the ultimate position. At the cessation of this'signal the armature I 26 is released, carrying the auxiliary driving member I61 radially out and causing the heel I12 thereof to. engage the retaining pawl and move it into inoperative position. The cam surface I13 simultaneously moves the pro.- pelling pawl away from the code plate. The part I 83 of the bracket is thereby moved. radially outward from the circular line. of travel of the pin I80, and the code plate is. thereby freed to return to starting position under the. influenceof its spring. I52;

Should. either of the first two integer signals be smaller than those described above, the code plate would not be advanced to the corresponding. A positions at theend of the last impulse, and when the armature I46. is. released the auxiliary driving member would not encounter a depending. pin I19a or I191); hence the member would not rotate about its pin I68 but the heel I12 would; engage the retaining. pawl, thereby freeing the codeplate for movement to starting; position under the influence of the spring L52. Should either of these signals be too large, the code plate would be advanced one step beyond the respective A position intothe corresponding B position; further advancement would be prevented by the corresponding blocking; deflector which prevents the entry of: thepropelling pawl into a notch. At the end of such. a large signal. the auxiliary driving member would similarly free the code plate for return to starting position. Should the third integer signal be either too small or too large the pin I88 would not be aligned with the part I83 of the bracket I-8I at the end of the last impulse and the outward movement of the slow-acting armature would not be arrested; the auxiliary driving member would, therefore, similarly free the code plate for return to starting position.

I claim as my invention:

1. In a code selective device, the combination of a code plate; propelling means for advancing the plate a controlled distance; blocking means for rendering said propelling means inoperative when the code plate is in a predetermined blocked position; and auxiliary driving means for advancing said plate beyond said blocked position only from a predetermined position of the code plate.

2. In a code selective device, the combination of a code plate; propelling means for advancing the plate; means for actuating the propelling means to advance the plate a controlled distance; blocking means for rendering said propelling means inoperative when the code plate is in a predetermined blocked position; auxiliary drive means for advancing said plate beyond said blocked position only from a predetermined position of the code plate; and means for actuating said auxiliary driving means to advance the plate following the operation of said propelling means.

3. The combination according to claim 2 wherein the plate has an engageable abutment and the auxiliary driving means comprises a movable driving member with an engaging toe adapted to engage the abutment when the code plate is in said other predetermined position.

i. In a code selective device, the combination of a code plate; means biasin said plate toward a starting position; propelling means for advancing the plate from starting position; retaining means cooperating with said plate and having an operative position for retainingthe plate in an advanced position and an inoperative position permitting retrograde movement of the plate; means for moving said retaining means to operative position; blocking means for rendering said propelling means inoperative when the code plate is in a predetermined blocked position; and auxiliary driving means for advancing said plate beyond said blocked position only from another predetermined position of the code plate in advance of said blocked position and for moving said retaining means to inoperative position to free the code plate for retrograde movement when the plate is at a position other than said other predetermined position when the auxiliary driving means is operated.

5. The combination according to claim l wherein the plate has an engageable abutment and the auxiliary driving means comprises a driving member mounted for rotation and reciprocation and having an engaging toe and an engaging heel, said heel being disposed to engage an element of said retaining means to move the latter to inoperative position upon operation of the auxiliary driving means and said engageable abutment on the plate being positioned thereon to be in alignment with said toe when the plate is in said other predetermined position for driving engagement of said toe with said abutment upon said operation, said toe being disposed with respect to the mounting of the driving member to cause rotation of said member upon engagement with said abutment to move the heel out of engaging position with respect to said element of the retaining means.

6. In a code selective device, the combination of a code plate having serrations; means biasing said plate toward a starting position; reciproc'able propelling means adapted to engage said serrations for advancing the plate stepwise from starting position; means for reciprocating said propelling means; retaining means cooperating with said plate having an operative position for retaining the plate in successive advance positions and an inoperative position permitting retrograde movement of the plate; means for moving said retaining means to operative position; blocking means on said plate covering one or more of said serrations to prevent driving engagement of the propelling means when the plate is in a predetermined blocked position; an auxiliary driving member pivotally mounted on a reciprocable support having a toe and a heel; means urging said driving member about its pivot to a normal position with the heel in alignment with an element of the retaining means for moving the retaining means to inoperative position when the reciprocable support is actuated; an abutment on the code plate positioned to be in alignment with the toe of the driving member when the code plate is in a second predetermined position in advance of said blocked position, said toe and pivotal mounting being disposed to ad vance the plate beyond the blocked position and to rotate the driving member to displace the heel thereof away from said element of the retaining pawl when the reciprocable support is actuated and the abutment is engaged; and means for actuating said reciprocable support subsequently to operation of said propelling means.

'7. In a code selective device adapted to respond to a composite "ode comprising a plurality of integer signals, the combination of a code plate; propelling means for advancing the plate during the reception of each integer signal for a controlled distance determined by the magnitude of the signal; blocking means for rendering said propelling means inoperative when the code plate is in a predetermined blocked position; auxiliary driving means for advancing said plate beyond said blocked position only from a second predetermined position of the code plate; m ans for actuating said auxiliary driving means after the reception of an integer signal; and means for operating a controlled device when the code plate is advanced to a predetermined third position after the reception of the last integer signal of said composite code.

8. In a code selective device adapted to respond to a composite code comprising a plurality of integer signals, the combination of a code plate having a series of serrations means biasing said plate toward a starting position; propelling means having a reciprocable element adapted to engage said serrations for advancing the plate stepwise from starting position; means for actuating the propelling means during the reception of each integer signal to advance the plate a number of steps determined by the magnitude of the signal; retaining means cooperating with said plate having an operative position for retaining the plate in successive advanced positions and an inoperative position permitting retrograde movem nt of the plate; means for moving said retaining means to operative position; blocking means for rendering said propelling means inoperative when the plate is in a predetermined blocked position; control means for moving the retaining means to inoperative position and free the plate for retrograde move ment at the end of each integer signal following the operation of the propelling means except when the said operation of the propelling means advanced the plate to one of several correct predetermined positions in accordance with thesaid code, at least one of said correct predetermined positions being in advance of and near to said blocked position; means for advancing the plate beyond said blocked position from said one correct predetermined position at the end of an integer signal; and means for maintaining the code plate in advanced position when the code plate is advanced to the last of said correct predetermined positions at the end of the last integer signal.

9. The combination according to. claim- 8 wherein the means for maintaining the. code plate in advanced position comprisesv an engagement member movable with the said control means for moving the retaining means to inoperative position and a cooperating abutment member on the code plate positioned thereon to be in. alignment with the said engagement member when the code plate is in said. last correct predetermined position for arresting. the movement of the said control means and preventing movement of the retaining means to inoperative position.

10. The combination according to claim 9 wherein the said engagement member and cooperating abutment member form contact. elements of an electrical switch, at least one of said members being electrically insulated from the code plate and said members being connected to a controlled circuit.

11. In a code selective device adapted to respond to a composite code comprising a plurality of electrical integer signals, the combination of a serrated code plate having a starting position, at least two advanced A positions corresponding to positions of the plate consequent upon the reception of successive correct integer signals, a blocked B position immediately beyond the first A position, and a C position beyond said B position; resilient means urging said plate to starting position; a reciprocable propelling pawl having an engaging; part engageable with said serrations for advancing the plate stepwise from starting position; a retaining the plate in successive advanced positions; means urging said retaining pawl into operative position; a blocking deflector on the plate positioned to prevent driving engagement of the propelling pawl with theserrations when the plate isin said B position; electromagnetic means comprising a fast acting armature for reciprocating saidpropelling pawl in synchronism with current alternations of said inte'ger signals; an auxiliary driving member mounted for reciprocating movement between first and second locations and supported for movement independent of said reciprocating movement to have a normal and a displaced position; an engaging toe and an engaging heel on said auxiliary driving member; said heel being positioned to engage an element of said retainin pawl when the driving member; isin the normal position thereof for moving: the said pawl to inoperative position and free the plate;

for retrograde movement when actuated for movement from said first to said second location while in normal position; abutment means: on the code plate positioned to be in alignment with the toe of the driving. member when the latter is in normal position andv the plate is in the first A position and adapted to be engaged by said toe when the driving member is moved from first to second location to advance the code plate from the said A position past the B taining pawl cooperating with said plate for reposition to the" said: C position,- the toe being positioned so that the driving member is moved from normal position to the displaced position thereof during such advancement to prevent. engagement of the heel with the element of the retaining pawl; electromagnetic means including a slow acting armature for holding said aux.- iliary driving member in said first location during the reception of said integer signals and for moving the auxiliary driving member to the second location subsequent to thecompletionoi each integer signal; and means for operating a. controlled device when the code plate: is advanced to the. last A position at the end of the last integer signal.

12. In combination with the device according to claim 11, an engagement member movable with said slow acting armature; and an abutment member on said code plate positioned thereon to be in alignment with the said engagementmemher when the code plate is in the said last A position for arresting the movement of said slow acting armature and preventing movement of the auxiliary driving to. the second location. thereof at the end of the last integer signal.

13. In a. code selective device adapted. to respond toa composite code comprising a plurality of electrical integer signals, the combination of a serrated code plate having a starting position,.. at least two advanced A positions corresponding to positions of the plate consequent upon the reception of successive correct integer signals, a blocked B position immediately beyond the first A position, anda C position beyond the said B position; resilient means urging said plate to starting position; a reciprocable propelling pawl having an engaging part engageable with said serrations for advancing the plate stepwise from starting position and pivotally mounted for movement away from said plate; resilient means urging said pawl into engagement with the plate;

a retaining pawl cooperating with said plate for retaining the plate in successive advanced positions; means urging said retaining pawl into operative position; a blocking deflector on the plate positioned to prevent driving engagement of the propelling pawl with the serrations when the plate is in said B'position; electromagnetic means comprising a fast acting armature for reciprocating said propelling pawl in synchronism with current alternations of said integer signals; a slow acting armature movable between first and second locations; electromagnetic means for holding said slow acting armature in the first location during the reception of an integer signal from the first to the second location while the driving. member is in the normal position, said means being located to be ineffective when the driving member is in the displaced position; anengaging toe on the auxiliary driving member;

* an abutment means on the code plate positioned thereon to be in alignment with said engaging toe when the code plate is in the first A position, said engagingtoe being located to advance the code plate past the B position to the said C position and to move the auxiliary driving member to the displaced position when the slow moving armature is moved from the first to the second location; and means for preventing engagement of the auxiliary driving member with the retaining pawl at the end of the last integer signal when the plate is advanced to the last A position at the end of said last signal.

14. The device according to claim 13 wherein the said means for preventing engagement of the auxiliary driving member with the retaining pawl comprises a second abutment means on the code plate positioned for alignment with the toe of the auxiliary driving member at said last A position.

15. The device according to claim 13 wherein the auxiliary driving member comprises resilient means urging it to said normal position; and the said means for moving the retaining and propelling pawls away from the plate comprises a heel on the driving member located for engagement with the retaining pawl and a cam surface adapted to engage the propelling pawl.

16. The device according to claim 13 wherein the electromagnetic means for moving the slow acting armature comprises a pair of windings connected in series, the first winding having a magnet controlling the fast acting armature and urging the slow acting armature to the second 26 location and the second winding having a magnet attracting the slow acting armature to the first location; resilient means normally urging the slow acting armature to the first location; a normally open time delay switch connected across the second winding; and means actuated by the operation of the fast acting armature for closing the switch at a time interval after movement of the fast acting armature.

17. The device according to claim 16 wherein the switch is a vibrating switch having an element adapted for vibrations and carrying an electrical contact for intermittently short circuiting the second winding while said member is vibrating and for short circuiting said winding continuously upon cessations of said vibrations.

HAROLD A. STICKEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 5 Number Name Date 2,359,494 Stickel Oct. 3, 1944 2,382,487 Kenny et al. Aug. 14, 1945 2,382,488 Kenny et al Aug. 14, 1945 

